Coastal change and conflict Flashcards
1
Q
What type of rock is easily eroded by the sea?
A
Soft rock
2
Q
Name a soft rock landscape
A
Bay
3
Q
What will landscapes be like if they are soft rock?
A
Less rugged and less steep than hard rock coasts
4
Q
What is hard rock resistant to?
A
All types of erosion
5
Q
What will hard rock landscapes be like?
A
Cliffs will be high, steep and rugged
6
Q
Name some hard rock landscapes
A
Wave-cut platforms and headlands where caves, arches and stacks are formed
7
Q
What are joints?
A
Small cracks in rocks
8
Q
What are faults?
A
Bigger cracks in rocks
9
Q
What do cracks and faults make rocks more vulnerable of?
A
Erosion
10
Q
What happens to rocks that have more cracks and faults?
A
They are eroded faster
11
Q
What are other factors of rates of erosion?
A
Geological structure
Wave climate
Local currents and tidal range
Groundwater levels
12
Q
What is geological structure?
A
If it is soft or hard rock
13
Q
What is wave climate?
A
How powerful waves are, wave direction, wave height
14
Q
If there is high groundwater what happens to the cliffs?
A
They become more saturated and are more vulnerable
15
Q
What are concordant coasts?
A
Coasts that are made up of the same type of rock and are parallel to the sea
16
Q
What are discordant coasts?
A
Coasts were the type of rock alternates in layers and are perpendicular to the sea
17
Q
What are normally formed at discordant coasts?
A
Headlands and bays
18
Q
Why are bays formed?
A
Due to rapid erosion of less resistant rocks such as clay
19
Q
What is formed due to the formation of a bay?
A
Headlands are left sticking out as they are made from hard rock, such as granite/chalk, which is resistant to erosion
20
Q
What are wave-cut platforms?
A
Areas of flat rock at the base of the cliff
21
Q
How is a stack formed?
A
When an arch collapses
22
Q
How is a stump formed?
A
When a stack is eroded by wind and water
23
Q
How is an arch formed?
A
When two caves erode back from either side of a headland and meet in the middle
24
Q
How is a cave formed?
A
When the waves erode a weakness in the rock such as a joint or a fault
25
How is a wave-cut platform eroded?
Wave-cut notch is undercutting by the waves while the rock face overhangs
Cliff retreats inland as the overhanging rock has collapsed
Wave-cut platform is formed
26
What is solution?
Chemical action by seawater on some rocks, especially limestone
27
What is attrition?
The rocks and pebbles carried by the waves rub together and break down into smaller pieces
28
What is abrasion?
Breaking waves throw sand and pebbles against the coast during storms
29
What is hydraulic action?
Waves compress air into the cracks in the rock, forcing them apart and weakening the rock
30
Describe a destructive wave
The swash is weak and the backwash is strong, which means material is dragged back down a beach into the sea
31
What are the impacts of the uk climate on coastal erosion
Prevailing winds
Seasons
Storm frequency
32
Explain the impact seasons have
For example in winter, cold temperatures lead to freeze-thaw weathering in cliffs
33
Explain the impact prevailing winds have
They come form the south-west, bringing warm, moist air from the Atlantic and frequent rainfall, leading to weathering and mass movement on the coast
34
Explain the impact storm frequency has
Is high in many parts of the UK so coasts often receive strong winds, which lead to an increase of eroding power waves and rainfall causing mass movement
35
What is a type of mechanical weathering?
Freeze-thaw
36
What is freeze-thaw?
When water seeps into cracks and freezes and expands. Over time the crack will widen and pieces of rock will fall off
37
What is biological weathering?
It is caused by plants and animals and its actions speed up mechanical and chemical weathering
38
What is an example of biological weathering?
Tree roots widen gaps in rocks
39
When does chemical weathering happen?
When a rock's mineral composition is changed
40
What is an example of chemical weathering?
Limestone is dissolved by carbonation.
41
What is carbonation?
Carbon dioxide in the atmosphere combines with rainwater to form carbonic acid, which changes limestone into calcium bicarbonate. This is then carried away by water in solution
42
What is mass movement?
The downhill movement of material under the influence of gravity
43
What do the different types of mass movement depend on?
The material involved
The amount of water in the material
The nature of the movement
44
How are slumps formed (mass movement)?
When the rock is saturated with water and slides down a curved slip plane
45
How does sliding happen (mass movement)?
When loosened rocks and soil suddenly tumble down the slope
46
What is coastal retreat?
When the coastline moves further inland
47
What does coastal erosion lead to?
Coastal retreat
48
Describe longshore drift
Waves approach the coast at an angle
Swash pushes sand gravel up the beach at the same angle
Backwash carries sand and gravel backdown the beach at 90degrees under the force of gravity
Sand and gravel move along the beach in a zigzag
Sand is lighter than gravel so moves further up
the beach
49
How do waves transport material?
Traction
Saltation
Suspension
Solution
50
What is traction?
Large boulders are rolled along the seabed by waves
51
What is saltation?
Smaller stones are bounced along the seabed
52
What is suspension?
Sand and small particles are carried along tin the flow
53
What is solution?
Some minerals are dissolved in seawater and carried along in the flow
54
Describe a constructive wave
The swash is strong but the backwash is weak. The wave is long in relation to its height so the crest breaks forwards
55
What are the different factors that influence deposition?
Sheltered spots (bays)
Calm conditions
Gentle gradient offshore causing friction
56
What do all the factors do to the wave's energy?
Reduce it
57
How are curved beaches formed?
By waves refracting or bending as they enter the bay
58
What are spits?
Narrow projections of sand or shingle that are attached to the land at one end
59
How are spits formed?
By longshore drift powered by a strong prevailing wind
60
How are bars formed?
By longshore drift that deposits material away from the coast until a long ridge is built up
61
What do bars form?
They form lagoons as they grow right across the bay, cutting of water
62
What impacts has development had on coastal landscapes?
Weight of buildings increase cliff vulnerability
Changes in drainage increase saturation
Raises interest in protecting coastal landscapes
63
What impacts has industry had on coastal landscapes?
Causes noise/air/soil/water pollution
Destroys natural habitats for birds, animals and sea life
Brings wealth and jobs to the area
64
What impacts has agriculture had on coastal landscapes?
Increased soil erosion
Increased sedimentation
Wildlife habitats may be created and preserved
65
What impacts has coastal management had on coastal landscapes?
Can increase further coastal erosion
Helps reduce risk of coastal flooding
Salt marches, sand dunes, sand bars and spits are preserved and protected
66
What impacts has tourism had on coastal landscapes?
```
Increased development of hotels
Increased pollution
Increased revenue benefits people living there
Increased desire to preserve landscape
Increase of coastal defences being built
```
67
What happens when atmospheric temperatures rise?
Storm frequency can increase so height and strength of waves will increase. Rainfall from storms will increase erosion and mass movement
68
What happens when sea temperature increases?
Water expands so sea levels rise (thermal expansion). Also ice will melt adding water to the ocean
69
What does sea levels rising put at risk?
Low-lying coastal land is at a higher risk of flooding
70
What are the effects of climate change of costal erosion?
Erosion may increase
Depositional features such as spits will disappear
Natural ecosystems and habitats may be destroyed
71
What are some impacts increased flooding has on people?
Can put people at risk of injury or death (storm surges)
Settlements need to be moved or defended, which is expensive
Coastal tourism will decrease
Loos of agricultural land will affect food production and economy
72
What are examples of hard engineering?
Sea walls
| Groynes
73
What are examples of soft engineering?
Beach replenishment
| Slope stabilisation
74
What are the advantages and disadvantages of sea walls?
Protects cliffs and buildings
| Expensive
75
What are the advantages and disadvantages of groynes?
Prevents sea removing sand
| Exposes other areas of coastline
76
What are the advantages and disadvantages of beach replenishment?
Sand reduces wave energy and maintains tourism
| Expensive
77
What are the advantages and disadvantages of slope stabilisation?
Reduces slippage
| Foot of cliff still needs protection from the waves
78
What are examples of integrated costal zone management ?
Do nothing
Hold the line
Strategic realignment
79
What are the advantages and disadvantages of doing nothing?
Cheap
| Homes and land are lost
80
What are the advantages and disadvantages of holding the line?
Existing shoreline is maintained
| Expensive
81
What are the advantages and disadvantages of strategic realignment?
People and activities move inland
| Unpopular with local residents
82
What is significant about Holderness coast's location?
Rock type is soft clay so it easily eroded and is prone to slumping when saturated
Exposed to strong waves
Harder chalk rocks at Flamborough head
83
What is the mean rate of erosion for Holderness coast?
2m/year
84
What physical processes are at work at Holderness coast?
Coastal erosion-coast is eroded rapidly
Transportation- strong waves move material away
Mass movement- slumps
85
What human processes are at work at Holderness coast?
Hard engineering- rock armour and groynes have protected some areas from erosion and cliffs collapsing
86
What changes have been caused at Holderness coast?
Farmland, property and settlements have been lost to the sea
